As an operating speed of electric products increases, a swing width of a signal that is interfaced between semiconductor devices decreases gradually. The reason is that a delay time taken in signal transmission needs to be minimized. However, as the swing width of the signal decreases, an influence of an external noise increases and also reflection of an output signal due to impedance mismatch at an interface stage becomes critical.
The impedance mismatch is caused by external noise, variation in a power source voltage, change in an operating temperature, and change in a manufacturing process. When the impedance mismatch occurs, high speed transmission of data may be difficult and data as an output signal that is output at a data output end of the semiconductor device may be distorted. Accordingly, when a semiconductor device at a receiving side receives the distorted output signal at an input end, problems such as a setup/hold fail or an input level decision error may frequently occur.
In order to apply an automatic impedance matching system, a technology for effectively integrating essential R-L-C is required. However, since an ultrasonic device uses a low frequency band of 20 to 40 MHz, passive elements have great values for integrating R-L-C and thus occupy large areas in a semiconductor. However, integration technology has limitations. Thus, it is difficult to implement element values that are variable for each channel on the board.
However, as systems are miniaturized, element values required for R-L-C matching are relatively reduced. Accordingly, if respective element values are reduced and determined an impedance matching function required thereto in a systematic situation between respective systems or nodes, performance of an entire system may be enhanced to the maximum extent possible.
The present invention is directed to providing an impedance matching device and method for effectively integrating R-L-C by adding a frequency converter to an input or output end of the impedance matching device.
One aspect of the present invention provides an impedance matching device comprising: a matching element array unit configured with a matching element array to which a transmission pulse and a received pulse pass, the transmission pulse being output from a system and the received pulse being the transmission pulse that is output to an outside and then reflected; an extraction/calculation unit extracting pulse information from the transmission pulse and the received pulse, calculating impedance values corresponding to the pulse information with respect to each of the transmission pulse and the received pulse, and calculating an impedance value having best response characteristics of the received pulse with respect to the transmission pulse as a matching impedance value; an array control unit routing the matching element array unit according to the matching impedance value; a first converter converting a frequency of the transmission pulse into a carrier frequency and outputting the carrier frequency to the matching element array unit; a second converter converting the carrier frequency output from the matching element array unit into a low frequency; and a converter control unit outputting a signal for controlling the frequency converting of the first converter and the second converter.
Another aspect of the present invention provides an impedance matching method comprising: converting a received transmission pulse into a predetermined carrier frequency to transmit the converted transmission pulse to a matching element array; extracting pulse information from the transmission pulse passing through the matching element array; converting the transmission pulse having passed through the matching element array from the carrier frequency to the original frequency to transmit the converted transmission pulse to an outside; receiving a received pulse corresponding to the transmission pulse; transmitting the received pulse to the matching element array configured to convert the received pulse into a carrier frequency; extracting pulse information from the received pulse passing through the matching element array; calculating a matching impedance value using the pulse information of the transmission pulse and the received pulse; and routing the matching element array through which the transmission pulse and the received pulse pass according to the matching impedance value.
The present invention can effectively integrate R-L-C elements that are essentially required for impedance matching to implement a programmable logic device (PLD) by adding a frequency converter to an input or output end of a source in order to reduce values of the R-L-C elements.
In addition, the present invention can overcome limitations of R-L-C integration technology for impedance matching between a probe and a system that operate in an existing ultrasonic sampling frequency range.